1. Field of the Invention
This invention generally relates to a reduced drag steering device. More particularly, the invention relates to a steering device for an underwater vehicle that uses a selectively ejected drag reducing medium to steer the vehicle.
2. Description of the Prior Art
The current art for steering underwater vehicles is by means of rudders or other similar protruding mechanisms. In the case of many underwater vehicles, there is a need for a more streamlined approach to steering. In particular, torpedoes need compact steering mechanisms in order to fit inside of torpedo tubes. Other craft require compact steering mechanisms to run at shallow depths, or to reduce the chance of fouling. Further, torpedoes, submarines, and other vehicles require smooth streamlined steering mechanisms to reduce drag and noise.
The following patents, for example, disclose drag reducing methods or underwater steering, but do not disclose the use of a selectively ejected drag reducing medium to control steering of an underwater vehicle.
U.S. Pat. No. 2,969,759 to Giles;                U.S. Pat. No. 3,096,739 to Smith;        U.S. Pat. No. 3,382,739 to Swanson;        U.S. Pat. No. 3,604,661 to Mayer, Jr.;        U.S. Pat. No. 3,628,488 to Gibson; and        U.S. Pat. No. 4,186,679 to Fabula et al.        
Specifically, Giles discloses hydrodynamic drag reduction in vehicles through boundary layer control. The device includes a plurality of slit means integral with the surface of the vehicle to permit a suction flow, duct means operatively associated with the slit means for carrying the suction flow to the stern of the vehicle, pump means operatively coupled to the duct means for generating and maintaining the suction flow and for preventing any hindrance to the suction flow at the surface of the vehicle, and means for reversing the suction flow.
The patent to Smith discloses a method and apparatus for steering underwater bodies of the type having a surface adjacent which water is adapted to flow and produce hydrodynamic force lateral to the direction of movement of the body and includes the steps of delivering a gas in a quantity insufficient to produce a jet reaction steering force but in a quantity sufficient for flow adjacent the surface to spoil the water flow and produce a different lateral hydrodynamic force on the body.
Swanson discloses a torpedo drag reduction apparatus. Sheets of an ablative and water soluble material containing a drag reducing polymer agent are mounted on a labyrinth of baffles in an annular cavity underneath the nose fairing of a torpedo. Ambient seawater, under ram pressure, is ingested by scoops and introduced into the rear end of the chamber. As the seawater circulates through the baffle labyrinth it dissolves the polymer agent contained in the ablative sheets. The front end of the annular chamber is communicated with the exterior of the surface of the torpedo hull by a circumferential slot which extends continuously about the torpedo. The solution of seawater and polymer, resulting from the circulation of the water through the labyrinth, issues forth through the slot into the boundary layer flow under the ram pressure.
Mayer, Jr. discloses a vehicle movable through a fluid-supporting medium and includes an active system for controlling the layer of fluid over at least a portion of the vehicle exterior surface. Parallel slots through the surface permit fluid under pressure to issue over the surface to reduce drag and improve lift and/or propulsion.
The patent to Gibson discloses an elongated flexible strip incorporating a longitudinally extending central tube provided with egress openings and is wrapped about the hull portion of a boat adjacent its bow. A chemical is fed into the central tube and passes out in controlled quantities from the egress openings to thereby form with water passing by the hull a diluted solution which then passes down the length of the hull and thereby reduces the friction of the boat hull when passing through water.
Fabula, et al. disclose a method and apparatus for reducing torpedo drag in which polymer drag reducing material is carried by the torpedo in concentrated form, ambient water is ingested and mixed with the concentrated polymer to produce a seawater-polymer solution of predetermined concentration, and the solution is ejected from the torpedo nose to be swept rearward in intimate contact with the exterior surface of the torpedo under torpedo forward motion.
It should be understood that the present invention would in fact enhance the functionality of the above patents by providing a steering mechanism for an underwater vehicle, in which the steering mechanism includes the selective ejection of a drag reducing polymer from a periphery of the vehicle.